Hello,
I'm new to this thread and I'm really impressed with the capabilities of the firmware of Bench Box 3 tool.
A few years ago I've started a similar hobbyist project called Labtool, supporting the usage of the various measurement modules. My device consists of the backplane with slots for up to 10 add-on modules, housed by a laser-cut metal housing.
The main capabilities of a backplane are:
- 7 inch LCD, 800x480 (or 6.5'' 400x240 with touch capability)
- MCU STM32F429 2MB Flash with external 32MB SDRAM, 64MB SPI Flash and battery backup RTC
- bunch of embedded interfaces like ethernet, 2xUSB, RS232, RS485, LIN, 2xCAN, I2C, SPI, UART, PWM, DIO, AIO
The purpose to design this tool was the need to have a freely programmable test & measurement device, capable to run even complicated test sequences thanks to PLC-like firmware. The idea reflects the capability to use each of the existing I/O and it's set of capabilities (like the current, voltage, baud rate, duty cycle, frequency, phase, etc.) as a parameter or result storage of any logic or arithmetic sub-block.
Each I/O card, sized 60x122mm, communicates with a backplane through 32-pin connector, providing +5/+12 supply, 16MHz system clock, SPI, I2C, and a few dedicated bi-directional lines. On every card exists small I2C configuration memory, which provides card information (like name, type, calibration data, etc.) during the initialization phase or after hot-swap.
Up to now I've designed and tested six different modules: 6-channel relay board, 8-channel high side driver module, 2 and 4 channels DDS signal generator, spectrum analyzer DC-50MHz, dual programmable resistor decade, and a 4-quadrant power supply +-20V/+-2A
. And of course, the port extension for debugging
. Some photos are attached herein.
Unfortunately, this project consumed me a lot of time and due to other professional activities was not yet fully finalized, mostly its software part. So this is why I'm impressed with the complete functionality of your design.
In a case someone will find this design useful, I can share schematics and some build guidance.